The present invention relates to cutter bit assemblies for use with coal ploughs.
As is known a coal plough is moved along a coal face to strip coal therefrom by a planing action performed by a plurality of cutter bits. These cutter bits are subjected to high rates of wear, especially in the case of hard coal, and it is generally necessary to replace or re-sharpen the bits to achieve optimum performance. Usually the cutting edges themselves are provided by hard metal attachments. It is thus necessary to design the cutter bits to facilitate their replacement or removal in the difficult cramped working conditions in the mine working. This is especially the case with shallow coal seams where space is severely limited. The problem of replacement is also aggravated by the fact that it is sometimes desirable with known designs to provide a variety of cutters of different size to cope with the prevailing seam conditions.
It is a general object of this invention to provide a cutter bit assembly where a wide range of cutter part designs can be employed and where the attachment and detachment of the cutter parts can be performed simply. It is a further object of the invention to provide a cutter bit assembly where the cutter part is reliably secured to cope with all the forces acting on the assembly during its use.